1. Field of the Invention
The present invention relates to a cosmetic preparation comprising a UV filter combination of 4-(tert-butyl)-4′-methoxydibenzoylmethane, 2,4,6-tris[anilino(p-carbo-2′-ethyl-1′-hexyloxy)]-1,3,5-triazine (INCI: Ethylhexyl Triazone), 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI: Bis-Ethylhexyloxyphenol methoxyphenyl Triazine), and 2-phenylbenzimidazole-5-sulfonic acid and/or one or more salts thereof.
2. Discussion of Background Information
The trend away from a gentile pallor toward “healthy, sportily brown skin” has been unbroken for years. In order to achieve this, people expose their skin to solar radiation, since this brings about pigment formation in the sense of melanin formation. However, the ultraviolet radiation in sunlight also has a damaging effect on the skin. Besides the acute damage (sunburn), there is long-term damage such as an increased risk of suffering from skin cancer on excessive irradiation with light from the UVB range (wavelength: 280-320 nm). Moreover, the effect of too much UVB and UVA radiation (wavelength: 320-400 nm) is a weakening of the elastic and collagenous fibers of the connective tissue. This leads to numerous phototoxic and photoallergic reactions, resulting in premature skin aging.
In order to protect the skin, therefore, a range of photoprotective filter substances have been developed that can be used in cosmetic preparations. In the majority of industrialized countries, these UVA and UVB filters are collated in the form of positive lists such as Annex 7 of the German Cosmetics Ordinance.
The multiplicity of commercially available sunscreen compositions should not, however, distract from the fact that these prior-art preparations have a range of disadvantages.
Because of factors including their UV filter content, cosmetic sunscreen compositions usually have a certain stickiness, which particularly in beach use means that sand ends up adhering to parts of the skin to which cream has been applied. The greater the UV filter content of a preparation, the greater this problem. While in the past there has been no lack of attempts to develop sand-repellent sunscreen compositions, this problem has nevertheless to date not been solved to ultimate satisfaction, particularly in the case of preparations featuring a high sun protection factor.
It would thus be advantageous to have available a sand-repellent sunscreen composition, more particularly a sunscreen composition having a high sun protection factor (SPF 50 or more) that exhibits particularly low sand adhesion.
In addition to the stickiness/sand adhesion, moreover, a problem of cosmetic sunscreen compositions is that very many UV filters do not have particularly good solubility in the preparations. Especially if preparations with a high sun protection factor and high UV filter content are developed, the developers face the problem of the solubility of triazine derivatives and 4-(tert-butyl)-4′-methoxydibenzoylmethane. In the past, in order to solve this problem, the liquid UV-B filter octocrylene has been used as UV filter and solvent.
A further disadvantage of the prior art lies in the circumstance that a range of further ingredients in sunscreen compositions are unstable to light and/or are destroyed or undergo volatilization under thermal exposure. The photoinstability of the UV-A filter and 4-(tert-butyl)-4′-methoxydibenzoylmethane poses a particular challenge in this context. Octocrylene, preferably, is likewise used according to the prior art for the photostabilization of 4-(tert-butyl)-4′-methoxydibenzoylmethane.
The disadvantage of the prior art lies, then, in the circumstance that the use of octocrylene, in spite of its approval by the approval authorities, is not entirely uncontroversial and results, when evaluations are undertaken in certain consumer magazines (e.g., the German Öko-test), in “markdowns” in the scoring of the product. The reason given for this negative evaluation is that certain scientists suspect that this UV filter might possibly have hormonal activity. Even when no negative effects in people have become apparent in spite of the decades-long use of this UV filter worldwide in sunscreen compositions, there is still a desire among consumers to avoid preparations containing such ingredients.
It, therefore is desirable to overcome the disadvantages of the prior art and to develop a sand-repellent sunscreen composition with a high sun protection factor, in which the UV filters are stably dissolved and the photochemical degradation of 4-(tert-butyl)-4′-methoxydibenzoylmethane is suppressed. Ideally it ought to be possible to achieve the object without using octocrylene as solvent and stabilizer.